If you look deeply enough online- they have a powder test or something in regard to porting and air's ability to escape out the porting - and then a reference to how that would impact sound signature.
I forget the reasoning and site and whatever - but it was the reason I opted for a Freak style tip this time around. I personally own both tips at the same length. I notice very little difference - though I have seen more barrel breaks in the Freak tip than the All American. That could be placebo or coincidence though.
Live dangerously, 7 minutes at a time.